In recent years, a controversy has sprung up around the time-honored and very popular tradition of backyard bird feeding. Once viewed as an unabashedly positive activity (“Look, I’m helping the birds!”), a couple of recent studies done in the U.K. have indicated that feeder-fed blue tits and great tits (relatives of the chickadee) laid fewer eggs, had lower hatching success, and ultimately fledged fewer chicks. (The question of “why?” was not answered.) It is important to note that these are only a few studies amongst many that have shown positive benefits. Other studies have shown the exact opposite impact: earlier laying dates, larger clutch size, and higher overall breeding success. A study of chickadees in Wisconsin showed a dramatically improved over-winter survival rate (69% for feeder-fed birds, vs. 37% for non-feeder-fed birds). (For more details, see here: http://blog.nature.org/science/2015/01/05/winter-bird-feeding-good-or-bad-for-birds/.).
So, what’s a nature-lover to do? I tend to err on the “feed” rather than the “not-feed” side, given the preponderance of evidence – and, for better or for worse, the fact that I enjoy backyard birdwatching. I currently have only two feeders: a standard tube-type, which I fill with sunflower seeds, and a suet feeder. That’s not a lot of feeders, and the birds don’t come very often; only every few days, rather than all day, every day, as has been my prior experience. I suspect that a neighbor provides a better food supply, and the birds only come to my yard when that runs dry. Alas! If the ground wasn’t frozen, I might add some more feeders. In the interim, I am investigating a heated water supply, though this is probably unnecessary, as birds have long-since adapted to northern winter weather without such fancy, modern devices.
For a brief but thorough and non-commercial summary of bird feeding tips, see Minnesota DNR’s page, here: http://www.dnr.state.mn.us/birdfeeding/winter/index.html